NATO has pledged to extend its reach beyond Europe and its traditional missions of conventional defense and peacekeeping to join the war on terrorism. The decision came after US Defense Secretary Donald Rumsfeld warned the allies that their cities could be hit by terrorist strikes like those that killed more than 3,000 people on September 11.

Mr. Rumsfeld's message to the allies was stark but clear. Brace yourself, he said, for ingenious and deadly attacks from terrorists prepared to use everything from cruise missiles to nuclear, chemical or biological weapons.

The US defense chief's remarks were made behind closed doors, but reporters were given copies of his speech. Later, Mr. Rumsfeld told a news conference what he had told his 18 NATO colleagues. "I expressed our concern with the overlap between the listed states that sponsor terrorism and terrorist networks, given the fact that a large number of the so-called terrorist states have active chemical, biological and/or nuclear programs," he said. "The nexus between states with weapons of mass destruction and terrorist networks raises the danger that September 11th could be a preview of what could come if the enemies of freedom gain ability to strike our nations with weapons of increasingly greater power."

NATO Secretary General George Robertson called on the ministers to face up to the cost of revamping the alliance, which was created more than 50 years ago to stave off Soviet expansionism, to meet the new threat of terrorism. Mr. Robertson says the ministers understood his message. "We recognize that the fight is far from over, and today we restated our resolve for zero tolerance of terrorism," he said. "This is a changed world with a premium on political and military agility, and NATO defense ministers understand this and are responding accordingly."

Mr. Robertson also said the allies are prepared to abandon their reluctance to confine NATO's operations to Europe. "In reviewing our defense plans, we agreed to increase the proportion of forces that can be deployed and sustained in operations far beyond alliance territory," he said.

Mr. Rumsfeld, too, said it is essential that, if the allies are to deal forthrightly with global terrorism, they will have to take the battle to the terrorists, wherever they may be. "The only way to deal with a terrorist network that is global is to go after it where it is," said the defense secretary.

Mr. Rumsfeld said the only alternative to seeking out and destroying the terrorists is to sit back and take the blows they strike. And that, he said, is foolhardy and dangerous and self-defeating.